Tag: WT1190F

Clouds hampered observations from the ground in Sri Lanka during the re-entry of WT1190F overnight, but a team of astronomers captured spectacular images of the object from a high-flying plane over the Indian Ocean very close to the predicted time of arrival.

Peter Jenniskens of the SETI Institute and NASA Ames Research Center is shown here before the flight setting up the eleven staring cameras with a wider field of view, including two spectographic cameras, to catch the reentry. Credit: IAC/UAE Space Agency/NASA/ESA

The International Astronomical Center (IAC) and the United Arab Emirates Space Agency hosted a rapid response team to study the re-entry of what was almost certainly a rocket stage from an earlier Apollo moon shot or the more recent Chinese Chang’e 3 mission. In an airplane window high above the clouds, the crew, which included Peter Jenniskens, Mike Koop and Jim Albers of the SETI Institute along with German, UK and United Arab Emirates astronomers, took still images, video and gathered high-resolution spectra of the breakup.

Video and still imagery of WT1190F’s Reentry November 13, 2015

The group of seven astronomers hoped to study WT1190F’s re-entry as a test case for future asteroid entries as well as improve our understanding of space debris behavior. Photos and video show the object breaking up into multiple pieces in a swift but brief fireball. From the spectra, the team should be able to determine the object’s nature — whether natural or manmade.

Wide view of the colorful fireball and breakup when WT1190F struck Earth’s atmosphere. More than 20 cameras were used to record the event. Credit: IAC/UAE Space Agency/NASA/ESAAnimation from photos made on Nov. 12 when WT1190F was still in one piece in orbit about the Earth. Credit: Marco LangbroekFlying observatory. This Gulfstream 450 business jet, sponsored by United Arab Emirates and coordinated by Mohammad Shawkat Odeh from the International Astronomical Center, Abu Dhabi, was used by the team to observe and record the re-entry. Only five windows were available to make observations. Credit: IAC/UAE Space Agency/NASA/ESASETI Institute “staring cameras” used for wide field observations of the re-entry. Credit: IAC/UAE Space Agency/NASA/ESA

No one’s 100% certain what WT1190F is — asteroid or rocket stage — but we are certain it will light up like a Roman candle when it re-enters Earth’s atmosphere around 6:20 Universal Time (12:20 a.m. CST) tomorrow morning Nov. 13.

Animation by Jost Jahn of WT1190F’s final hours as it races across the sky coming down off the coast of Sri Lanka

As described in an earlier story at Universe Today, an object discovered by the Catalina Sky Survey on Oct 3rd and temporarily designated WT1190F is expected to burn up about 60 miles (100 km) off the southern coast of Sri Lanka overnight. The same team observed it twice in 2013. Based upon the evolution of its orbit, astronomers determined that the object is only about six feet (2-meters) across with a very low density, making it a good fit for a defunct rocket booster, possibly one used to launch either one of the Apollo spacecraft or the Chinese Chang’e 3 lander to the Moon.

Below a plot of the last three orbits of WT1190F. The small red circle is the Earth. For scale, the large green circle is the orbit of the Moon. Notice that its final orbit takes straight into Earth. Credit: Bill Gray / Project Pluto

Additional observations of WT1190F have been made in the past few days confirming its re-entry later tonight. Checking the latest predictions on Bill Gray of Project Pluto’s page, the object will likely be visible from Europe about an hour before “touchdown”. To say it will be moving quickly across the sky is an understatement. Try about 3 arc minutes per second or 3° a minute! Very tricky to find and track something moving that fast.

Three 90-second exposures showing WT1190F zipping across the Rosette Nebula taken on Nov. 11, 2015 at the Konkoly Observatory in Hungary. Credit: Krisztián Sárneczky

58 minutes later, in the minute of time from 6:18 to 6:19 UT, WT1190F will move one full hour of right ascension and plummet 34° in declination while brightening from magnitude +8 to +4.5. If you’d like to attempt to find and follow the object, head over to JPL’s Horizons site for the latest ephemerides and orbital elements. At the site, make sure that WT1190F is in the Target Body line. If not, click Change and search for WT1190F in the Target Body field at the bottom of the window.

WT1190F re-Entry Trajectory. The object is expected to break up and fall harmlessly into the ocean. Credit: Bill Gray, Project Pluto

You’ll find updates at Bill Gray’s site. According to the most recent positions, the object will pass almost exactly in front of the Sun shortly before plunging into the ocean. Sri Lanka’s capital, Colombo, is expected to get the best views.

Because the mystery object’s arrival has been fairly well publicized, I hope to update you with a full report and photos first thing tomorrow morning. Like many of you, I wish I could see the show.

Get ready for a man-made fireball. A object discovered by the Catalina Sky Survey on Oct 3rd temporarily designated WT1190F is predicted to impact the Earth about 60 miles (100 km) off the southern coast of Sri Lanka around 6:20 Universal Time (12:20 a.m CST) on November 13.

The object orbits Earth with a period of about three weeks. Because it was also observed twice in 2013 by the same survey team, astronomers have the data they need to model its orbit and trajectory, and as far anyone can tell, it’s likely man-made.

The first two stages of the Saturn V rockets used to send the seven Apollo missions to the Moon fell back to Earth, but the third stage (S-IVB), pictured here, propelled the spacecraft into a lunar trajectory. Could this be WT1190F? Credit: NASA

Solar radiation pressure, the physical “push” exerted by photons of sunlight, is proportional to a space object’s area-to-mass ratio. Small, lightweight objects get pushed around more easily than heavier, denser ones. Taking that factor into account in examining WT1190F’s motion over two years, the survey team has indirectly measured WT1190F’s density at about 10% that of water. This is too low to be a typical asteroid made of rock, but a good fit with a hollow shell, possibly the upper stage of a rocket.

Spectacular re-entry of the Jules Verne ATV-1 cargo ship over the Pacific Ocean on September 29, 2008. Still image from a TV camera operated by Jessie Carpenter and Bill Moede of NASA Ames Research Center. A similar spectacle is expected on November 13 south of Sri Lanka.

It’s also quite small, at most only about six feet or a couple of meters in diameter. Most or all of it is likely to burn up upon re-entry, creating a spectacular show for anyone near the scene. During the next week and a half, the European Space Agency’s NEO (Near-Earth Object) Coordination Centeris organizing observing campaigns to collect as much data as possible on the object, according to a posting on their website. The agency has two goals: to better understand satellite re-entries from high orbits and to use the opportunity to test our readiness for a possible future event involving a real asteroid. The latter happened once before when 2008 TC3(a real asteroid) was spotted on October 6, 2008 and predicted to strike Earth the very next day. Incredibly, it did and peppered the Sudan with meteorites that were later recovered.

Assuming WT1190F is artificial, its trans-lunar orbit (orbit that carries it beyond the Moon) hints at several possibilities. Third stages from the Saturn-V rockets that launched the Apollo missions to the Moon are still out there. It could also be a stage from one of the old Russian or more recent Chinese lunar missions. Even rockets used to give interplanetary probes a final push are game.

Near-Earth object J002E3 discovery images taken by Bill Yeung on September 3, 2002. The 16th magnitude object was tentatively identified as the Apollo 12 third stage rocket. Animation created by Bob Denny.

Case in point. What was thought initially to be a new asteroid discovered by amateur astronomer Bill Yeung on September 3, 2002 proved a much better fit with an Apollo 12 S-IVB (third) stage after University of Arizona astronomers found that spectra taken of the object strongly correlated with absorption features seen in a combination of man-made materials including white paint, black paint, and aluminum, all consistent with Saturn V rockets.

On April 14th 1970, the Apollo 13 Saturn IVB upper stage impacted the moon north of Mare Cognitum. The impact crater, which is roughly 30 meters in diameter, is clearly visible in this photo taken by the Lunar Reconnaissance Orbiter. Credit: NASA/Goddard/Arizona State University

Apollo 13’s booster was the first deliberately crashed into the Moon, where it blew out it a crisp, 98-foot-wide (30-meter) crater. Why do such a crazy thing? What better way to test the seismometers left by the Apollo 12 crew? All subsequent boosters ended their lives similarly in the name of seismography. Third stages from earlier missions — Apollos 8, 10 and 11 — entered orbit around the Sun, while Apollo 12, which is orbiting Earth, briefly masqueraded as asteroid J002E3.

The nominal impact point is located about 60 miles south of the island nation Sri Lanka. Given the object’s small size and mass, it will likely be completely incinerated during re-entry. Credit: Bill Gray at Project Pluto

Bill Gray at Project Pluto has a page up about the November 13 impact of WT1190F with more information. Satellite and asteroid watchers are hoping to track the object before and right up until it burns up in the atmosphere. Currently, it’s extremely faint and moving eastward in Orion. You can click HERE for an ephemeris giving its position at the JPL Horizons site. How exciting if we could see whatever’s coming down before its demise on Friday the 13th!